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"ABSTRAKTujuan dari penelitian ini adalah untuk membandingkan efektivitas campuran enzim selulase kasar dari Trichoderma reeseidan Aspergillus niger dengan selulase A. nigerkomersial dari Fluka Biochemika serta mempelajari pengaruhratio enzim dengan substrat terhadap unjuk kerja hidrolisis. Enzim kasar dibuat dengan cara fermentasi padat denganmedia sederhana. Satu unit aktivitas selulase kasar dariA. niger dicampur dengan dua unit aktivitas selulase kasar dariT. reesei. Jerami padi yang akan dihidrolisis terlebih dahulu digiling dan diayak 120?140 mesh kemudian didelignifikasimenggunakan larutan NaOH 2% selama 6 jam pada temperatur 85oC. Hidrolisis dilakukan dalam beaker glass 300 mLyang dilengkapi dengan pengaduk bermotor. Sampel dianalisis menggunakan metoda dintrosalicylic acid. Hasilpercobaan menunjukkan bahwa peningkatan rasio enzim terhadap jerami padi dapat meningkatkan konsentrasi glukosayang dihasilkan baik untuk enzim komersial maupun campuran enzim kasar. Campuran enzim selulase kasar dari T.reesei dan A. nigeryang dihasilkan dari percobaan ini, dua kali lebih efektif menghidrolisis jerami padi menjadi glukosa dibandingkan dengan selulase komersial.

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AbstractThe objective of this work is to compare the effectiveness of mixed crude enzyme cellulase from T. reesei and A. niger with commercial enzyme from A. niger, and to investigate effect ofenzyme to substrate ratio to performance of enzymatic hydrolysis of rice straw. The commercial enzyme from FlukaBiochemica was used, and crude enzyme were prepared by solid fermentation with simple media. Before hydrolized,the rice straw was grinded and sieved and then heated at 85oC with 2% sodium hydroxide for six hours. Hydrolysis wasconducted in 300 mL beaker flask equipped with mechanical stirrer. Samples were analyzed by dinitrosalicylic acidmethod and measured by spectrophotometer. Both of commercial and mixed crude enzyme show that, the higherenzyme to substrate ratio washigher the glucose concentration obtained. However, ratio of glucose obtained to enzymeused become smaller. The mixture of crude enzyme from T. reesesidan A. niger that produced in this work was two fold more effective to hydrolyze rice straw than using cellulase enzyme of A. nigerfrom Fluka Biochemika. "

"Nanostructured zincoxide (ZnO) was synthesized via a sonochemical method. The effect of the duration of ultrasonic irradiation in a continuous mode on the generated particles was investigated. Additionally, the effect of flowing either air or nitrogen during the sonication process was investigated. Zinc nitrate andammonia water-based solutions were selected as chemicals without the additionof other surfactants. The generated particles indicated that a wurtzitestructure of ZnO in a hexagonal phase was formed with a crystalline size that increasedas the ultrasound irradiation time increased. The morphology of the generatedZnO particles could be changed from flowerlike to needlelike structures viacontinuous ultrasound irradiation over one to two hours, resulting in increasesin the particle lengths and decreases in the particle diameters from 200 to 80nm. Photoluminescence intensity was also increased with increases in the ultrasonicirradiation times. Photoluminescence spectra were also influenced by theatmospheric environment. Two bands centered at 390 and 500 nm were generatedunder a nitrogen environment. On the other hand, a single wide band with a peakat around 430 nm was found for particles generated under an air environment. Itcan be applied for light emitting diodes (LED) or laser fabrication with acontrolled emitting band."